| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 6°F | 25°F | 15°F | 1.9" |
| February | 11°F | 30°F | 20°F | 0.6" |
| March | 22°F | 44°F | 32°F | 3.2" |
| April | 34°F | 57°F | 44°F | 5.0" |
| May | 45°F | 72°F | 58°F | 3.2" |
| June | 56°F | 81°F | 68°F | 5.3" |
| July | 59°F | 85°F | 71°F | 7.2" |
| August | 57°F | 82°F | 69°F | 6.8" |
| September | 47°F | 74°F | 59°F | 3.5" |
| October | 37°F | 61°F | 48°F | 4.7" |
| November | 27°F | 47°F | 36°F | 2.5" |
| December | 12°F | 30°F | 20°F | 1.3" |
| Index | Grand Marsh | Wisconsin | National |
| Air quality index | 35 | 69 | 42 |
| Pollution index | 1,548,770 | 2,842,418 | 2,726,193 |
| Measurement | Total |
| Days measured | 365 |
| Days with good air quality | 311 |
| Days with moderate air quality | 53 |
| Days w/ poor A.Q. for sensitive groups | 1 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.003% |
| Benzene | 0.020% |
| Carbon Tetrachloride | 0.002% |
| Lead | 0.001% |
| Mercury | 0.003% |
| City | Population | Air Quality Index | National Avg. |
| Coloma, WI | 573 | 35 | 30.0% |
| Oxford, WI | 558 | 35 | 30.0% |
| Dellwood, WI | 486 | 35 | 30.0% |
| Westfield, WI | 1,293 | 35 | 30.0% |
| Adams, WI | 2,224 | 35 | 30.0% |
| Grand Marsh, WI | 148 | 35 | 30.0% |
| City | Population | Air Quality Index | National Avg. |
| Atmautluak, AK | 148 | 31 | 38.0% |
| Tanacross, AK | 148 | 38 | 24.0% |
| Orrville, AL | 148 | 52 | 4.0% |
| Bellville, GA | 148 | 39 | 22.0% |
| Ayrshire, IA | 148 | 15 | 70.0% |
| Grand Marsh, WI | 148 | 35 | 30.0% |